Roller chain and link for conveyers



Dec. 5, 1939. H. A. M ANINCH 2,182,443

ROLLER CHAIN AND LINK FOR CONVEYERS Filed Dec. 7, 1957 4 Sheets-Sheet 1 Dec. 5, 1939. H. A. MCANINCH ROLLER CHAIN AND LINK For: CONVEYERS 4 Sheets-Sheet 2 Filed Dec. '7, 1937 5, 1939. H. A. M ANINCH ROLLER CHAIN AND LINK FOR CONVEYERS Filed Dec. '7, 1937 4 Sheets-Sheet 5 Dec; 5, 1939. H. A. MCANINCH 2,182,443.

ROLLER CHAIN AND LINK FOR CONVEYERS Filed Dec. 7, 1937 4 Sheets-Sheet 4 Patented Dec. 5, 1939 2 132 443 Q UNITED. STATES PATENT; OFFICE BOILER CHAIN AND LINK FOR CONVEYERS Herbert a McAninch, Indianapolis, Ind., assignor toisLink-Belt Company, a. corporation of Illino Application December 7, 1937, Serial No. 178,621 7 Claims. (Ci. 74-250) This invention relates to new and useful improvements in roller chain and link constructions for conveyer assemblies.

It has been determined that the strength of of operating at higher speeds is growing steadily, improvement in the strength-weight ratio becomes of great importance for excessive weight has a very destructive eifect in the. matter of impact loads and centrifugal tension.

In an eifortto effect improvements in such chains, experiments and tests have been conducted to ascertain the proper distribution of material being used to bring about the greatest strength for a link and/or chain from the standpoint of impact, fatigue and ultimate strength and to obtain the most favorablestrength-weight ratio and as close a balance of stresses as is possible' in keeping with the proper distribution of materials. These experiments involved, among other things, a determination of the points of most frequent failures of chains and chain links and a study ofstresses affecting the various elements comprising an individual link while being subjected to load conditions.

Such experiments developed several very inter- I esting, enlightenin and unpredictable facts, some 7 of which were:

(1) In roller chains made up of conventional links having straight or flat side plates, wherein the sections of material carrying the load are equal in each link, the strength of the inside link members is greater than the strength of the outside members.

(2) In roller chains employing ofiset links. either throughout the entire assembly or as couplers when an odd number of pitches in the total chain length is desired, the narrower ends of the links; 1. e., the ends of the links which are positioned between the side plates of the next adjacent links, are stronger than the wider ends.

(3) Links having side plates formed with straight longitudinal edges are stronger than links having curved longitudinal edges, such as those found'in "dumb-bell links.

(4) The removal of material from the center of a side plate, preferably over an area extending transversely of the plate to an extent substantially equal to the diameter of the pitch holes,

holes to mount the chain pins which pass through and are journaled in the bores of said bushings. If this difference was responsible for the differences in strength, the ratios of the pitch hole diameter to the dimensions of the material around the pitch holes must be factors which govern the strength of chain links and the provision of a greater amount of material around a pitch hole, although contrary to what might be expected, would not provide greater strength. Experiments were conducted with this feature in mind and it was determined that there exists a combination ofproportions which would give, when used as a group, a strength value in the critical stress sections consistent with the strength of the material used and a balance between the strengths of inside and outside links and the opposite ends of individual offset links.

It was found that any departure from this combination of proportions, involving any one or more of the elements of the combination, would result in an appreciable lowering of the strength embodying said links. This combination of pro- .portions deals primarily with dimensions in the 5 chain, as being manufactured today, i n t equal not only effects a reduction in the weight of the 5 to the strength of the minimum cross section of plate but it increases its stren t With aid inmaterial involved in the individual link members, creases being n d t p p rti n to the n ease as evidenced by the fact that the ultimate breakin material removed D the Point ere 0 ins strength is considerably under the strength material remains between e W0 pitch 0 8- 10 of the minimum cross section. This clearly in In an efiort t ascertain reasons for t e facts dicates that such chains r capable of being recited in the above paragraphs identified as 1 materially improved, for, failing to take full adand 2, ins de d Outs l s a pp s vantage of available material strength, they can end portions of ofiset'links were carefully o hardly possess the best strength-weight ratio p ed. What app d to be'the most ts a d- '15 obtainable. As the demand for chains capable ing difference between these compared parts was value of the aifected links and, naturally, a chain patterns produced by the differently constructed chain link side plates when subjected to load conditions.

It was determined that in straight edged side plates, the stress or force flow lines extended the full length of the plates without interruption and with substantially no deflection of such lines in the regions'of the longitudinal edges of the plates. whereas in curved edged side plates, many of the stress or force flow lines did not extend the full length of the plates and a marked deflection was present in all lines which did extend the full length.

The explanation for the increase in the strength or stress value resulting from the removal of material from the centers of the links was found to be due to the reduction or elimination of concentration of stress or force flow lines on the opposite transverse sides of the pitch holes and to reducing or entirely eliminating stress or force flow lines which extended longitudinally of the centers of the plates and were deflected around the opposite transverse sides of the pitch holes. Naturally, this elimination of material from the centers of the side plates eiiected a material improvement in the strength-weight ratio.

In keeping withthe above discoveries, the primary objects of this invention are to provide roller chains and links in which proper proportions or combinations of dimensions and a proper distribution of material are employed to produce maximum strength characteristics with minimum weight; a minimum of stress and asclose a balance of stresses as is possible; the greatest ter and amount of material used, and a balance of strength between the different links of a chain assembly-and the different portions of individual links when the areas of stress in all of the links are maintained equal.

Other objects and advantages of the invention will be apparent during the course of the iollowing description.

In the accompanying drawings forming a part of this specification and in which like numerals are employed to designate like parts throughout the same,

Figure l. is a plan view of a type of conveyer chain embodying this invention,

Figure la isa side elevational view of the section of chain illustrated in Fig. 1,

Figure 2 is a top plan view of a modified form of conveyer chain which embodies this invention,

Figure 2a is a side elevational view 01 the section of chain disclosed in Fig.2,

Figure 2b is an end elevational view of the section of chain disclosed in Figs. 2 and 2a,

Figure 3 is a plan view or a section of a still further modified form of conveyer chain embody- 1118 this invention,

Figure 3a is a side elevational view of the section of chain disclosed in Fig. 3,

Figure 4 isa top plan view of another form of conveyer chain embodying this invention,

Figure 4a is a side elevational view of the section 01 chain illustrated in Fig. 4,

. Figure 5 is a side elevational view of a chain link side plate of the type now conventionally employed, said side plate being of the straight link Figure dis a side elevatioual view of a. chain proved features of construction ultimately resulting from the development of this invention,

Figure '7 is a side elevational view of a. chain link side plate which incorporates in its construction improved features in addition to those disclosed in the side plate illustrated in Fig.6,

Figure 8 is a, side elevational view-oi a chain link side plate which further illustrates the ad vancement made by this invention,

Figure 9 is a side elevational view a chain link side plate which includes all of the features of construction produced by the development of this invention,

Figure 10 is a side elevational view of a chain link side plate embodying all of the features of the side plate illustrated in Fig. 9, but illustratw a slight modification of one element of the side plate,

Figure 10a is a transverse sectional view taken. on line loaf-Na of Fig. 10.

Figure 11 is a side elevational view of a side plate of the type employed in oflset links,

Figure 11a is an edge plan view of the link side plate disclosed in Fig. 11,

Figure 11b is a transverse sectional view taken on line llbl lb of Fig. 11a,

Figure 110 is a transverse sectional view taken on. line Hc-Hc of Fig. 1111.

Figure 12 is a side elevational view of a modifled form of chain link side plate of the type disclosed in Fig. 11, I

Figure 12a is an edge plan view of the chain link side plate disclosed in Fig. 12, and

Figure 13 is a transverse sectional view of a modified form of chain pin and bushing assembly for chains.

The advancements made in the art by this invention deal with improvements in the ultimate developments of the improvements embodying thisinvention in the side plates of flat links and ofiset links. These figures, therefore, first will be referred to. l

The development of the invention in link side plates of the straight link type is fully illustrated in Figs. to s, inclusive. Fig. 5 discloses a single side plate of a link of thetype conventionally referred to as a dumb-bell" link. i

This type of link is standard construction for probably all manufacturers of roller chains. The link side plates include the relatively narrow central portion l 5 with the two enlarged ends I. Each end It is provided with a pitch hole l'l. Chains made up of links employing this type of Such improved chain straight side, plates are composed of pivotally connected, alternately arranged inside and outside links. The pitch holes H for the inside links are formed or a proper diameter to mount bush-. ings or tubular sleeves. The two side plates and the two bushings or sleeves which form an inside link are connected by a press fit to prevent pitch holes for the inside links. The inside and outside links of a chain of this type are provided with side plates wherein the sections of material carrying the load are equal in each side plate and complete link. vTheinside links, however, are provided with pitch holes of greater diameter than the pitch holes of the outside links.

As has been pointed out above, it was determined that a chain formed of links including side plates of the type disclosed in Fig. 5 does not have the strength of the minimum cross section of material involved in the individual link members. It was also determined that inside links formed with pitch holes of large diameters to receive the bushings possessed greater strength than did the outside links which have the smaller diametered pitch holes. As a result of determining that chains of this dumb-bell link type do not take full advantage of available material strength and that an unbalanced strength condition existed between inside and outside links, experiments were conducted with links having side plates of many different shapes and combinations of proportions.

As a result of these experiments, it was determined that a link possessing straight longitudinal edges on its side plates was stronger than a link formed of side plates having curved longitudinal edges, such as the dumb-bell link of Fig. 5. It, also, was determined that the inside links are stronger than the outside links because the inside links are formed with side plates possessing a more favorable combination of proportions in the regions of the pitch holes or critical stress sections.

ratios of dimensions in the plane of the face of a side plate. Ascertaining the difference in strength between inside and outside links led:

to the discovery that the diameter of a pitch hole formed the basis for all of the remaining dimensions involving the material surrounding a pitch hole. For the purpose of comparing relative strengths of link side plates of different shapes and dimensional combinations, formulas were established as follows:

Let

A equal the diameter of the pitch hole,

B equal the width of the side plate,

C equal the distance from the outer edge of the pitch hole to the end of the side plate on the center line,

T equal the thickness of side plate,

Rw equal the ratio of the widthof the side plate to the diameter of the pitch hole,--

Rr. equal the ratio of the distance between the pitch hole and the end of the side plate to the width of the side plate minus the pitch hole diameter, and

K equal the stress ratio.

The above ratios are computed as follows:

Maximum stress across critical section Average stress on an area BT In Fig. 5. the formula characters A, B and C have been applied to the'left-hand end of the link side plate disclosed. It will be appreciated that roller chains produced by the various manufacturers are standardized so th'at'the chains of The combination of pro---' portions found to be most desirable deals with;

different manufacturers may be interchangeably used on standard sprockets" of given pitches and numbers of teeth. This standardization necessitates the use of rollers, bushings and chain pins of substantially uniform dimensions in the chains of the different manufacturers. The pitch hole'diameters, therefore, are substantially identical in all of the chains of a givenlink size which are manufactured by the different roller chain producers.

Chain link side plates of the type shown in Fig.

5 were measured insofar as the dimensions A, B and C are concerned, for a large number of different sized links and for a great many of the chains manufactured by different producers.

It was found that the following values prevailed:

It will be noted that this link is provided with 7 straight longitudinal edges l8 and with pitch holes IS. The straight longitudinal ed'ges ill for this plate are equal in length to the pitch of these links. The Rw ratio of this link side plate was changed to .5. The R1. ratio'was kept the same as. that for the side plate of Fig. 5.

This link side plate was found to possess the following stress ratio: K=2.53. It will be appreciated that the lower stress ratio K a link side plate possesses, the stronger the side plate. This side plate of Fig. 6, therefore, proved to be stronger than the side plate shown in Fig. 5.

The right-hand portions of the side plates shown'in Figs. 5 and 6 have been provided with; dash lines which are intended to represent the 7 stress fiowline patterns produced in these side plates when subjected to load conditions. It is believed that these stress flow line patterns provide an excellent explanation why a chain link.

side plate having straight longitudinal edges is stronger than one having curved longitudinal edges. In Fig. 5, it will be seen that several of the stress flow lines occurring in the outer regions of the enlarged end portion 16 do not extend the entire length of the link side plate. All of the stress flow lines in the link side'plate disclosed in Fig. 6 are permitted to extend longitudinally of the side plate without interruption through the center of the plate because of the elimination of the reduced central portion 15 of l the side plate.

shown in Fig. 5.

Fig. '7 illustrates a further modified form of link side plate. This link side plate is provided greater length than the pitch of the said plate; i. e., the straight longitudinal edges 20 extend well beyond the pitch holes 2|. This link side plate was further modified by increasing the C with'straight longitudinal edges 20 which are of dimension. This link of Fig. 7 possessed the the side plates shown in Figs. 6 and 7, it will be seen that the lengthening of the dimension C permits all of the flow lines to continue uninterruptedly around the outer side of the pitch hole.

Experiments also were conducted in an endeavor to improve the strength-weight ratio by removing material from the center of the side plate. This modification was found to not only reduce the weightoi' a side plate, but it materially 1o improved the stress ratio. It was ascertained that the stress ratio became lower each time more material was removed from the center of the side plate. This improvement continued until all of the material was removed from between the two pitch holes. Fig. 8 illustrates a link side plate with all the material removed from between the pitch holes.

- This link side plate possessed the same A, B and C measurements as thelink side plate shown in m Fig. 'I. The Rw and the R1. values or ratios for the side plate of Fig. 8, therefore, are the same as for the side plate shown in Fig. 7. It was found, however, that the side plate of Fig. 8 possessed a K (stre$ ratio) of 1.97 which constituted a 5 marked improvement over the K value of the side plate disclosed in Fig. 7. I

It is believed that the improvement in the stress ratio resulting from the removal of material from the center of a link side plate is indicated by the 30 diilerence in the stress flow line patterns for the side plates of Figs. 7 and 8. By considering the disclosure of Fig. 7 it will be seen that the flow lines which extend through the transverse central region or the side plate continue around the op- '3 posite sides of the pitch hole and result in a' concentration of flow lines on the opposite transverse sides of the pitch hole. In Fig. 8, this concentration of stress flow lines on the opposite sides of the pitch hole 22 is eliminated. All of the stress 40 flow lines extend continuously the full length of the side plate and around the outer sides of the pitch holes. None of the stress flow lines, furthermore, are deflected in flowing from the cen- The link side plate of Fig. 8, it will be noted, employs the straight. longitudinal edges of the form of side plate shown in Fig. 'l. The dash lines 24 are provided merely for the purpose of completing the circle .of, each. pitch-hole 22 and. are not intended to indicate the presence of any material, I

It will be apparent that a linkside plate of the.

type shown in Fig. 8 cannot be used as a part of a chain link because no material is provided on the inner longitudinal sides of the pitch holes to support or mount tlieibushings'and chain pins.

chain pins must be provided. 5

pleting the pitch holes 20. The character M is employed to represent the width of this band. It has'been determined that the M value must ar 16 a certain ratio with respect to the thickness oi e Sufficient material to mount the bushings and Fig. 9 discloses a band oi material. fer comlink side plate. It will be appreciated that a link side plate, to carrya particular load; must possess the necessary amount of material in the load carryingsection. side plates having a given pitch hole'diame'ter, therefore, may be provided to carry difierent loads byvarying the thickness of the side plates.

It has, been found that thestrip or barrier material 25must be equal 'to'the thicknesso'i the link side plate if the side plate is to be punched or blanked from'astrip or sheet of stock. This amount of material is necessaryto provide-proper support for the material surrounding the' pitch holes being punched. If the material around the holes is too thin, it will actually roll or turn over and will not produce a good fit with the bushings or chain pins to be mounted therein. However,

if the link side plates are produced in a ma- I chining operation, the pitch holes can be drilled or reamed when much less material is provided in the bands 25.

The bands 25 in Fig. 9 are representative of the minimum amount of'material which can be provided on the inner sides or the pitch holes and yet properly sustain the bushings or chain pins mounted in said holes. In this chain link side plate, the M measurement is as follows:

M=L3T (T equals thickness of side plate) The dimensions A, B and C for the link side plate of Fig. 9 are the same as those for the side plate shown in Figs. 7 and'8. This link side plate of Fig. 9 has the following values:

It will be seen that rat addition of the band of material 25 has increased the stress ratio over that given above for the link side plate shown in Fig. 8. This stress ratio factor of 2.13 appears to be about the best that can be obtained for operative chain link side plate.

Fig. 10, with the sectional view Fig. 10a, illustrates a chain link side plate of the design shown in Fig. 9 with bands 21 at the inner sides of the pitch holes 28. In this link side plate, the dimension M equals the dimension T. The values for this plate of Fig. 10 flgure out as follows:

The stress ratio value is shown in this table as having been increased by the addition of more material in the band 21 provided for each pitch hole. As stated above, an increase in the K value represents a decrease in strength. The link side ever, that beneficial improvements can be obtained over the conventional link side plate shown in Fig. ii side plates are produced which fall within the following ranges of values:

Figs. 11 to 120. disclose side plates for offset links. It will be appreciated that the side plates disclosed in Figs. 5 to 10a are representative of either inside or outside links. When the above noted combination of proportions is followed in 15 producing a complete chain from inside and outside links, the inside links, naturally, will possess diflerent dimensions for the characters A, B, C, M,

N and T than the outside links. This difference in dimensions results from changing the dimension A to accommodate bushings which are mounted in the side plates of the inside links. The outside link side plates, of course, mount the smaller chain pins. links are comparable for approximately one-half of their length with outside links while the remainder are comparable with inside links. The pitch hole 29 must possess a diameter which will mount a chain pin while the pitch hole 30 must possess a diameter which will mount a bushing. 30 Figs. 11 to lie disclose an offset link constructed in accordance with the preferred combination of proportions set forth in connection with the side plate disclosed-in Fig. 7. No material has been removed from the center of this side plate. Figs. 12 and 12a disclose an offset link side plate constructed with the combination of proportions set forth for the side plate disclosed in Figs. 10 and 10a. The values for M and N are the same for the side plate of Figs. 12 and 12a as have been iven for these characters of the link disclosed in Figs. 10 and 10a. In carrying out the same combination of proportions for the opposite halves of an offset link side plate, the opposite endsv of the link side plate naturally-are of different widths. Both halves of such a side plate also should possess the same cross sectional area through the critical sections. Figs. 11b and 110 clearly illustrate the diiference in dimension for p the character T for these two sections. As the bands 3i and 32, of the side plate shown in Fig.

12, are formed of material of difierent thicknesses, the M values will be different. Although it is impossible to providelongitudinal edges in ofiset links which are straight in the same sense as are the longitudinal edges for the link side plates disclosed in Figs. 6 to 10, inclusive, the longitudinal edges 33 are disclosed in Figs. 11 and 12 as being maintained as near as possible in a single plane; i. e., a single plane for each longitudinal edge.

Let us now consider Figs. 1 to 4a, inclusive, which illustrate the adoption of the invention described in connection with Figs. 6 to 12a, inclusive, in conveyer chains of different types.

Referring first to Figs. 1 and lo, we find disclosed a conveyer chain made up entirely of inside and outside links. The side plates for the inside links are designated by the reference character 33 while the side plates for the outside links are identified by the reference character 34. The

inside links are provided with pitch holes 35, see the right-hand link of Fig. 1a, of a proper diameter to mount the bushings 36. The outside links 35 are provided with pitch holes 31 oi. a proper diameter to mount the chain pins 38, lit

The side plates of offset will be seen that the chain pins not only pass through the pitch holes 31 of the outside links 34, but also pass through the bores of the bushings 36 to pivotally connect the inside and outside links. The bushings 36 not only perform 5 their duty to pivotally connect the links, through the medium of the pins 38, but they act as bearings for the rollers 39. In applying the combination of proportions described in connection with either Fig. 9 or Fig. 10 to the inside and-out- 10 side link side plates 33 and 34, the difierence in 'thediameters of the. pitch holes 35 and 31 results in the provision of inside link side plates 33 which are wider than the outside link side plates while the said outside link side plates 34 are 15 thicker than the side plates 33. A chain constructed as shown in Figs. 1 and 2, which follows the desired combination of proportions previous ly referred to, possesses .an absolute balance of strength between the inside and outside links. 20

At suitably spaced intervals throughout the entire length of a chain constructed of links of the type shown in Figs. 1 and la, conveying lugs 40 are formed as integral parts of the inside and outside plates 33 and 34. These lugs may func- 2 tion to push articles to be conveyed along a track or trough or the lugs may be suitably apertured or modified in construction to permit them to mount article conveying plates, buckets, or the like, not shown. 30

Figs. 2, 2a and 2b disclose a conveyer chain employing inside and outside links of the character shown in Figs. 1 and 1a. The disclosure of these latter figures, however, has been modified to 'illustrate the use of offset links in a conveyer 35.

chain constructed of inside and outside links. It will be appreciated that a chain which is composed of inside and outside links solely possesses an even number of pitches for it can'only be' modified with reference to its length by inserting 40 or removing a pair of links composed of. one inside and one outside link. When it is desirable to have a chain with an odd number of pitches, this can only be accomplished by inserting an offset link. For other reasons, it 45 may be desirable to insert two or more oil'set links in a chain composed primarily of inside and outside links. Figs. 2 and 2a disclose a secttion of conveyer chain with two offset links incorporated therein. The inside and outside 50 links are of the same construction as those disclosed in Figs. 1 and 1a and for that reason, the same reference characters will beapplied to similar elements in Figs. 2 and 2a. The side plates 4| for the two ofiset links are each pro- 55 vided with an end portion 42 which compares in proportions with one end portionof an outside link 34. These side plates 4| also are each provided with an end-portion 43 which compares in proportions with an end portion of. an inside 60 link 33. A chain constructed in this manner is found to possess a perfect balance of strength between the inside and the outside links. the said inside and outside links and the offset links, and

the opposite end portions or critical stress sec- 5 tions of all of the links.

,eiTect movement of objects along a supporting surface.

Figs. 3 and 3a disclose a'section of a conveyer chain which is-formed in its entirety ofoifset 75 links I. The narrower and thicker ends 42 of these links are provided with pitch holes 31 for mounting chain pins 33. The wider and thinner ends 43 are provided with pitch holes 35 of a 5 proper diameter to mount the bushings 36. The

ends 43 of the side plates II are positioned inside of the end portions 42 of the side plates for the adjacent links. This manner of assembling the various links is clearly illustrated in Figs. 3 and 30. To eflect conveying of articles, certain of the chain pins H are extended axially beyond one side of the chain and are enlarged to provide the projecting end portions 13.

Figs. 4 and 4a disclose what is commonly called a fiat top conveyer. This roller chain ismade up of inside links 66 and outside links 41. Each one of the link side plates is provided with an upstanding flange 56 which functions to mount a top carrier plate 49. These carrier plates are secured to the flanges d3 by means of peened over lugs 56 which are carried by the flanges 43 and are received in apertures or openings formed in the top plate. Other than being provided with the flanges and the top plate securing lugs 56. the side plates 46 and I! for the inside and outside links correspond structurally with the plates 33 and 3| of the chains disclosed in Figs. 1 to 2b. inclusive.

The chain assemblies disclosed in Figs. 1 to 4a inclusive, are provided with rollers 33 rotatab y mounted on bushings 36 which fllIlCtiOll to connect the side plate of inside links or the end portions of ofl'set link side plates which are relatively positioned the same as inside links. These Ilrollers naturally material y reduce sprocket wear.

Less expensive chains are provided .by most manufacturers which are interchan eable with the chains above referred to. but which do not have the separately rotatable rollers. In these chains,

40 the bushings are enlarged at their central portions to the diameter of the rol ers and the bushin s then also function to a limited extent as rollers. Fi 13' illustrates this modified type of combined bushing and roller.

It s to be understood that the side plates SI and 52 are intended to re resent either the side Plates of inside and outside links or the side plates of offset links. A combined bushina and rol er 63 is pro erly connected at its ends to so he s de lates 3|. The remaining side plates 52 are ri id y connected to ether and are pivota nnected to the side plates 5| by the chain D n 5 which passes throu h the bore of the element 33. The ch in in BI and combined bu hinc and roller '33 may be substituted for the. bushings 36. pins 38 and ro lers 33 inany r all of the chain assemblies of Fi s. 1 to do without in any way affect ng the advanta es provided by the side p ate desi ns shown therein. Y

00 It is believed that the fore oing description. when'c nsidered with the drawin s. will furni h one skilled in the art with a clear understanding of the im roved construction of the use of the d sclosed chain link side latenronortions and 65 structural changes. It mi ht be at this time that ultimate stren th tests have been made to compare the links disclosed in Figs. 9. 10. 11 and'12 with chain link side plates of conventional design produced by many menufacturers. It has been found that the links embod ing this invention effect an increase n strength over conventionallinks of approximately 19 per cent per inch of pitch over the best conventional chain and yet the strength per pound of 'weight is equivalent. Chains formed of the improved links embodying this invention are completely interchangeable with conventional chains designed for the same type of use and present no greater manufacturing problem:

It is to be understood that the forms of this 5 invention herewith shown and described are to be taken as preferred examples of the same, and that various changes in the shape, size, and arrangement of parts may be resorted to without departing from thespirit of the invention or the 10 scope of the subioinedclaims,

Having thus described the invention, I claim:

1. A chain length of the type described comprising a plurality of pivctally connected links, each of said links-including a-pair of side plates 15 formed with a pitch hole in each end portion of the same, the pivotal connections between adjacent links each including a pair of inside side. plate end portions connected by a bushing received in their pitchholes and a pair of outside 20 side plate end portions connected by a chain pin received in their pitch holes and which pin also passes through the bore of the bushing ofadjacent inside side plate end portions, the inside'side plate endportions each being of greater width 25 and less thickness on the transverse section passing through the pitch hole axis than each of the outside side plate end portions on a similar section, each pitch hole of all of said side plate end portions having a diameter which is from .45 to 30 .6 of the width of the side plate on its aforesaid transverse section and being spaced from its adjais from .6 to .95 of the difl'erence between the 35 aforesaid width of the side plate and the diameter of the pitch hole.

2. A chain length of the type described comprising a plurality of pivotally connected links, each of said links including a pair of side plates 40 formed with a pitch hole in each end portion of the, same, the pivotal connections between adiacent links each including a pair of inside side plate end portions connected by a bushing re ceived in their pitch holes and a pair of outside 45 side plate end portions connected by a chain pin received in theirpitch holes and which pin also, passes through the bore of the bushing of ad- Jacent inside side plate end portions, the inside side plate end portions each being of greater so width and less thickness on the transverse section passing through the pitch hole axis than each of the outside side plate end portions on a similar section, each pitch hole of all of said side plate" end portions having a diameter which is from .46 55 to .6 of the width of the side plate on its afore-' said transverse 'section'and being spaced from its adjacent end of the side plate a distance alone the longitudinal center line of the side plate which is from .6 to .95 ofthe difference between'the aforesaid width of the side plate and the diameter of the pitch hole, all of said side plates having the-same area on the aforesaid transverse sections which pass through the pitch hole axes.

3. A chain length of the type described comprising a plurality of pivotally connected links,- each of said links including a pair of side plates: formed with a pitch hole in each end portion of the same, the pivotal connections between adiacent links each including a pair of inside side Plate end portions connected bya bushing rccelved in their pitch holes and a pair of outside side plate end portions connected by a chain pin received in their pitch holes and which pin mo DassesthroughtheboreoftheDWhinIofad-JK.

similar section, each pitch hole of all of said side plate end portions having a diameter which is from .45 to .6 of the width the side plate on its aforesaid transverse section and being spaced-from its adjacent end of the side plate a distance along the longitudinal center line of the side plate which is from .6 to .95 of the difference between the aforesaid width of the side plate and the diameter oi the pitch hole, each of said link side plates having an opening formed in its central region which has a width adjacent each pitch hole that is substantially the same as the diameter of the pitch hole and a length which will leave a band of material on the inner side oi each pitch hole having a minimum width ranging from .3 to 1.5 of the thickness of the side plate through said band. 4. In a chain of the type described, a pluralit of link side plates each comprising an elongated body portion having a pitch holeiormed in each end portion and straight longitudinal edges which extend in both directions beyond the pitch holes, the diameter of each pitch hole being from .45 to .8 oi the width of the side plate on the transverse section which passes through the pitch hole axis and being spaced from its adjacent end of the side plate a distance along the longitudinal center line of the side plate which is from .6 to .95 o! the difference between the aforesaid width of the side plate and the diameter of the pitch hole whereby when said pitch holes are of a relative size to receive a link joint forming bushing the sidelplate will be wider and longer than when the said pitch holes are of asize to receive a link joint forming chain pin, said body portion havingan opening iormed in its central region which has a width that is substantially the same as the diameter oi the pitch hole and is of proper length toleave a band of material on the inner side of each pitch hole having a width rangin from .3 to 1.5 of the thickness of the side plate through said band. 4

5. A chain length of the type described comprising a plurality oi. pivotally connected alternating inside and outside links. each of said links including a pair of side plates formed with a pitch hole in each end portion of each of the same, the inside link side plates being connected together by bushings received intheir pitch holes, the outside link side plates being connected together by ansaus 7 chain pins received in their pitch holes and which pins also pass through the bushings at the ends oi the adjacent inside links, the inside link side plates being or greater width and less thickness on the transverse sections'passing through their pitch hole axes than the outside link side plates on similar sections, each pitch hole of all of said side plates having a diameter which is from .45 to .6 of the width of the side plate on itsaforesaid transverse section and being spaced from its adjacent-endoi the side plate a distance along the longitudinal center line of the side plate which is from .6 to .95 of the difierence between the aforesaid width of the side plate and the diameter of the pitch hole.

6. A chain length of the type described comprising a plurality of pivotally connected oilset .links, each of said links including a pair of side plates formed with a pitch hole in each end portion of each of the same, the pitch holes at one end oi the link mounting a bushing and the pitch holes at the other end mounting a chain pin to be journaled in the bushings of an adjacent link.

the end portions ofthe side plates which mountthe bushings being of greater width and less thickness on the transverse sections passing through their pitch hole axes than the chain pin mounting end portions on similar sections;

each pitch hole of all 61 said side plate end portions having a diameter which is from .45 to .6 of the width of the side plate on its aforesaid transverse section and being spaced from its adjacent end of the side plate a distance along the longitudinal center line of the side plate which is from .6 to .95 of the diflerence between the aforesaid width of the side plate and the diameter of the pitch hole.

'7. An offset chain link side plate comprising a body portion having a pitch hole in one end por-. tionto mount a bushing and a pitch hole in the other end portion to mount a chain pin, the end portion mounting the bushing being of greater width and less thickness on the transverse section passing through the pitch hole axis than the other end portion on a similar sectiomeach of said pitch holes having a diameter which is from .45 to .6 of the width of the side plate on its aforesaid transverse section and being spaced from its adjacent end of the side plate a distance along the longitudinal center line of the side plate which is from .6 .to..95 of the diflerence between the aforesaid width of theside plate and the diameter of the pitch hole.

HERBERT A. MoANINCH. 

